Cancer immunotherapy with immune checkpoint inhibitors (CPI) and interleukin (IL)-2 has demonstrated clinical efficacy but is frequently accompanied with severe adverse events caused by excessive and systemic immune system activation. Here, we addressed this need by targeting both the CPI antibodies anti-cytotoxic T-lymphocyte antigen 4 antibody (αCTLA4) + anti-programmed death-ligand 1 antibody (αPD-L1) and the cytokine IL-2 to tumors via conjugation (for the antibodies) or recombinant fusion (for the cytokine) to a collagen-binding domain (CBD) derived from the blood protein von Willebrand factor (VWF) A3 domain, harnessing the exposure of tumor stroma collagen to blood components due to the leakiness of the tumor vasculature. We show that intravenously (i.v.) administered CBD protein accumulated mainly in tumors. CBD conjugation or fusion decreases the systemic toxicity of both αCTLA4+αPD-L1 combination therapy and IL-2, for example eliminating hepatotoxicity with the CPI molecules and ameliorating pulmonary edema with IL-2. Both CBD-CPI and CBD-IL-2 suppressed tumor growth compared to their unmodified forms in multiple murine cancer models, and both CBD-CPI and CBD-IL-2 increased tumor-infiltrating CD8+ T cells. In an orthotopic breast tumor model, combination treatment with CPI and IL-2 eradicated tumors in 9 of 13 animals with the CBD-modified drugs, whereas it did so in only 1 of 13 animals with the unmodified drugs. Thus, the A3 domain of VWF can be used to improve safety and efficacy of systemically-administered tumor drugs with high translational promise.

ASP2151 is a novel herpes helicase-primase inhibitor that warrants further investigation for the potential treatment of both VZV and HSV infections.

Enhancing the therapeutic efficacy of drugs for inflammatory diseases is of high demand. One possible approach is targeting drugs to the extracellular matrix of the inflamed area. Here, we target collagens in the matrix, which are inaccessible in most tissues yet are exposed to the bloodstream in the inflamed area because of vascular hyperpermeability. We conferred collagen affinity to anti–tumor necrosis factor-α (α-TNF) antibody by conjugating a collagen-binding peptide (CBP) derived from the sequence of decorin. CBP–α-TNF accumulated in the inflamed paw of the arthritis model, and arthritis development was significantly suppressed by treatment with CBP–α-TNF compared with the unmodified antibody. Similarly, CBP–anti-transforming growth factor-β (α–TGF-β) accumulated in the inflamed lung of pulmonary fibrosis model and significantly suppressed pulmonary fibrosis compared with the unmodified antibody. Together, collagen affinity enables the anticytokine antibodies to target arthritis and pulmonary fibrosis accompanied by inflammation, demonstrating a clinically translational approach to treat inflammatory diseases.

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Current therapies against invasive pulmonary aspergillosis (IPA) have a limited cure rate. Given that a delay in treatment initiation may be fatal, a new drug with rapid-onset and potent fungicidal activity is needed. The novel cyclic hexapeptide ASP2397 (currently known as VL-2397) exhibited antifungal activity against Aspergillus fumigatus (including azole-sensitive and azole-resistant isolates), A. terreus, and A. flavus at an MIC range of 1 to 4 μg/ml in human serum. Time-kill curve experiments showed that ASP2397 reduced germinated conidia of A. fumigatus by more than 1 log10 CFU within 6 h. In addition, ASP2397 inhibited hyphal elongation from germinated conidia of A. fumigatus, A. terreus, and A. flavus more rapidly than voriconazole. Under conditions of delayed treatment initiation in an IPA mouse model, ASP2397 had efficacy superior to that of posaconazole, with 100% survival and over 1 log10 CFU/g reduction in lung fungal burden. Histopathological investigation of lungs also showed that ASP2397 markedly suppressed disease progression. To clarify its mechanism of action, we generated a UV-induced mutant of A. fumigatus with low susceptibility to ASP2397. The mutant had a point mutation in the siderophore transporter gene sit1, which is absent in mammalian cells. These findings suggest that ASP2397 may improve clinical treatment options for IPA.

Interleukin-4 (IL-4) suppresses the development of multiple sclerosis in a murine model of experimental autoimmune encephalomyelitis (EAE). Here, we show in mice with EAE that, compared with the administration of wild-type IL-4 or of the clinically approved drug fingolimod, the systemic injection of serum albumin (SA) fused to IL-4 better accumulates and persists in lymph nodes and in the spleen, leading to higher therapeutic efficacy and to the prevention of disease development in the majority of the mice. We also show that the SA-IL-4 fusion protein prevented immune-cell infiltration in the spinal cord, decreased integrin expression in antigen-specific CD4 + T cells, increased the number of granulocyte-like myeloid-derived suppressor cells (and their expression of programmed-death-ligand-1) in spinal-cord-draining lymph nodes, and decreased the number of T helper 17 cells, a pathogenic cell population in EAE. In mice with chronic EAE, SA-IL-4 inhibited immune-cell infiltration into the spinal cord and completely abrogated immune responses to myelin antigen in the spleen. The SA-IL-4 fusion protein may be prophylactically and therapeutically advantageous in the treatment of multiple sclerosis. Multiple sclerosis (MS) is a potentially disabling autoimmune disease that affects millions globally. Autoreactive immune cells home to the central nervous system (CNS) and cause demyelination and consequently focal damage to white matter 1 . Lymphocytes and macrophages that have infiltrated into the CNS cause axonal damage. Recent studies have shown that Th17 cells, activated in the secondary lymphoid organs (SLOs), migrate to the spinal cord and brain and play a crucial role in the disease development and severity of MS 2, 3 . Thus, inhibition of lymphocyte migration to the CNS and inducing an immune-suppressive microenvironment in the SLOs would provide an effective therapy for MS. FTY720 (fingolimod) and anti-integrin α4 antibody (natalizumab) are used in the clinic for treating MS 4, 5 , sequestering lymphocytes in the LNs and preventing them from reacting with autoantigens in target tissues. Experimental autoimmune encephalomyelitis (EAE) is a widely accepted murine model of MS, reflecting many features of disease progression and developmental mechanism, including lymphocyte migration to the CNS and demyelination.Interleukin (IL)-4 is a pleiotropic anti-inflammatory cytokine that differentiates naïve CD4 + T cells into a Th2 phenotype and results in decreased differentiation into Th1 and Th17 6 . IL-4 suppresses re-activation of committed Th17 cells 6 . Moreover, IL-4 polarizes macrophages toward the M2 phenotype, an antiinflammatory phenotype 7 . IL-4 has been reported to suppress EAE disease incidence and severity 8,9 ; this occurs not only through direct immuno-modulation, as a recent study has shown that intranasally administered IL-4 improved disease outcomes of EAE through IL-4 directly binding to neurons to promote regeneration 10 .Although IL-4 stimulates multiple pathways to suppress EAE, it has yet to be tr...

ASP2151 (amenamevir) is a helicase-primase inhibitor against herpes simplex virus 1 (HSV-1), HSV-2, and varicella zoster virus.Here, to determine and analyze the correlation between the pharmacodynamic (PD) and pharmacokinetic (PK) parameters of ASP2151, we examined the PD profile of ASP2151 using in vitro plaque reduction assay and a murine model of HSV-1 infection. ASP2151 inhibited the in vitro replication of HSV-1 with a mean 50% effective concentration (EC 50 ) of 14 ng/ml. In the cutaneously HSV-1-infected mouse model, ASP2151 dose dependently suppressed intradermal HSV-1 growth, with the effect reaching a plateau at a dose of 30 mg/kg of body weight/day. The dose fractionation study showed that intradermal HSV-1 titers were below the detection limit in mice treated with ASP2151 at 100 mg/kg/day divided into two daily doses and at 30 or 100 mg/kg/day divided into three daily doses. The intradermal HSV-1 titer correlated with the maximum concentration of drug in serum (C max ), the area under the concentration-time curve over 24 h (AUC 24h ), and the time during which the concentration of ASP2151 in plasma was above 100 ng/ml (T >100 ). The continuous infusion of ASP2151 effectively decreased intradermal HSV-1 titers below the limit of detection in mice in which the ASP2151 concentration in plasma reached 79 to 145 ng/ml. Our findings suggest that the antiviral efficacy of ASP2151 is most closely associated with the PK parameter T >100 in HSV-1-infected mice. Based on these results, we propose that a plasma ASP2151 concentration exceeding 100 ng/ml for 21 to 24 h per day provides the maximum efficacy in HSV-1-infected mice.

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